For twelve long years, the dread fortress of Azkaban held an infamous prisoner named Sirius Black. Convicted of killing thirteen people with a single curse, he was said to be the heir apparent to the Dark Lord, Voldemort. Now he has escaped, leaving only two clues as to where he might be headed: Harry Potters defeat of You-Know-Who was Blacks downfall as well. And the Azkban guards heard Black muttering in his sleep, Hes at Hogwarts...hes at Hogwarts. Harry Potter isnt safe, not even within the walls of his magical school, surrounded by his friends. Because on top of it all, there may well be a traitor in their midst.